> ## Documentation Index > Fetch the complete documentation index at: https://docs.coderabbit.ai/llms.txt > Use this file to discover all available pages before exploring further. # Read a saved Change Stack overview and layers > Omit snapshot_id for the latest saved artifact or supply one to pin an exact retained snapshot. Outdated artifacts remain readable. Null means no saved artifact exists; this operation never starts generation. ## OpenAPI ````yaml /openapi.json get /v1/repositories/{repository_id}/pull-requests/{pull_request_number}/change-stack openapi: 3.0.3 info: title: CodeRabbit API spec version: 1.0.0 servers: - url: https://api.coderabbit.ai security: - ApiKeyAuth: [] paths: /v1/repositories/{repository_id}/pull-requests/{pull_request_number}/change-stack: get: tags: - Reviews summary: Read a saved Change Stack overview and layers description: >- Omit snapshot_id for the latest saved artifact or supply one to pin an exact retained snapshot. Outdated artifacts remain readable. Null means no saved artifact exists; this operation never starts generation. operationId: get_pull_request_change_stack parameters: - name: repository_id in: path required: true schema: type: string minLength: 1 - name: pull_request_number in: path required: true schema: type: integer minimum: 0 maximum: 2147483647 exclusiveMinimum: true - name: org_id in: query schema: type: string allowEmptyValue: true allowReserved: true - name: snapshot_id in: query schema: type: string minLength: 1 allowEmptyValue: true allowReserved: true responses: '200': description: OK content: application/json: schema: type: object properties: current_head_sha: type: string artifact: anyOf: - type: object properties: snapshot_id: anyOf: - type: string - type: string nullable: true enum: - null created_at: type: string base_sha: anyOf: - type: string - type: string nullable: true enum: - null reviewed_head_sha: anyOf: - type: string - type: string nullable: true enum: - null title: type: string summary: type: string groups: type: array items: type: object properties: id: type: string title: type: string summary: type: string layers: type: array items: type: object properties: id: type: string title: type: string summary: type: string order: type: integer minimum: 0 maximum: 9007199254740991 depends_on: type: array items: type: string diagrams: type: array items: type: object properties: format: enum: - mermaid title: type: string source: type: string required: - format - title - source files: type: array items: type: object properties: path: type: string ranges: type: array items: type: object properties: side: enum: - old - new type: string start_line: anyOf: - type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true - type: string nullable: true enum: - null end_line: anyOf: - type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true - type: string nullable: true enum: - null summary: type: string required: - side - start_line - end_line - summary required: - path - ranges required: - id - title - summary - order - depends_on - diagrams - files required: - id - title - summary - layers coverage: type: object properties: unassigned_ranges: type: array items: type: object properties: side: enum: - old - new type: string start_line: anyOf: - type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true - type: string nullable: true enum: - null end_line: anyOf: - type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true - type: string nullable: true enum: - null summary: type: string path: type: string required: - side - start_line - end_line - summary - path excluded_files: type: array items: type: object properties: path: type: string required: - path required: - unassigned_ranges - excluded_files freshness: enum: - current - outdated - unknown type: string required: - snapshot_id - created_at - base_sha - reviewed_head_sha - title - summary - groups - coverage - freshness - type: string nullable: true enum: - null required: - current_head_sha - artifact '400': description: '400' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - invalid_request type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '401': description: '401' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - unauthenticated type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '403': description: '403' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - forbidden type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '404': description: '404' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - not_found type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '409': description: '409' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - head_changed - conflict type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '412': description: '412' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - precondition_failed type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '413': description: '413' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - payload_too_large type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '429': description: '429' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - rate_limit_exceeded type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '500': description: '500' content: application/json: schema: type: object properties: error: type: object properties: code: enum: - internal_error type: string message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false '503': description: '503' content: application/json: schema: type: object properties: error: type: object properties: code: type: string enum: - unavailable message: type: string retry_after: type: integer minimum: 0 maximum: 9007199254740991 exclusiveMinimum: true required: - code - message additionalProperties: false required: - error additionalProperties: false components: securitySchemes: ApiKeyAuth: type: apiKey in: header name: x-coderabbitai-api-key description: >- API key for authentication. You can create an API key from the CodeRabbit dashboard. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.